Gas range or similar appliance



y 935-v B. E. MEACHAM 2,040,011

GAS RANGE 0R SIMILAR APPLIANCE Filed Oct. 6, 1933 3 Sheets-Shee t 1 \R R IN \QS 3 5 .3 .1 m n n Ls R4 K 3 N N Q up w R N I J 121:. N x L 2 Gm, wg z WQLQW May 5, 1936. B. E. MEACHAM GAS RANGE 0R SIMILAR APPLIANCE 3 Sheets-Sheet 2 Filed Oct. 6, 1955 momma M 35% Q MLU/u dam/M1 May 5, 1936. B. E. MEACHAM GAS RANGE OR SIMILAR APPLIANCE I Filed Oct. 6, 1953 3 Sheets-Sheet 3 Patented May 5, 1936 PATENT OFFlCE GAS RANGE R SIMILAR APPLIANCE Benjamin Edward Meacham, Lorain, Ohio, as-

signor to American Stove Company, St. Louis, Mo., a corporation of New Jersey Application October 6, 1933, Serial No. 692,533

11 Claims. (Cl. 158-1171) The present invention relates to new and useful improvements in gas ranges or similar gas appliances. The primary object of the present invention is the provision of an improved automatic lighter equipment for use in connection with gas ranges or similar appliances.

' A further object of the invention is the provision of an automatic lighter equipment for gas ranges or similar gas appliances wherein the equipment is so designed as to prevent the escape of unburned or raw gas from any of the range burners.

A still further object of the invention is the provision of a safety valve for use in combination with an automatic lighter equipment on gas ranges or similar gas appliances wherein the operation of the safety valve is under the control of two pilot lights.

L Other specific objects, novel features of construction and improved results of the invention will appear in more detail in. the following description when read in the light of the accompanying drawings.

Another and still further object of the invention is the provision of an automatic lighter and control device which is both dependable and efficient in operation and which by reason of being comprised within a comparatively few number of parts can be readily assembled and is simple and cheap of manufacture.

'In the drawings:

Figure l is a top plan view of a range equipped with the present invention, a portion of the range being shown in horizontal section to more clearly illustrate the arrangement of parts.

Fig. 2 is a view in front elevation, a portion of the view being in vertical section to more clearly illustrate the arrangement of the parts constituting the invention, the view being taken on the line 2--2 of Figure 1;

Fig. 3 is a vertical sectional view through the safety valve, the view being taken on the line 3-3 of Figure 1;

Fig. 4 is a vertical sectional view through the constantly burning pilot light and the valve which is thermostatically operated thereby.

Fig. 5 is a horizontal sectional view through the same structure appearing in Figure 4 of the drawings; the view being taken on the line 5-5 of Figure 4.

In considering the following description it is to be borne in mind that the improved automatic lighter arrangement has in combination with it a safety feature which absolutely prevents the escapage of unburned gas from either the cooking top or oven burners of the range illustrated in the drawings and hereinafter described.

The escapage of unburned gas may occur in many ways, chief among which are the extinguishing of the flame at a burner by reason of a 5 boil over or a heavy draft which extinguishes the flame at the burner by blowing it out. Another common way in which unburned gases escape from an unlighted burner is through the accidental opening of a valve controlling the supply of gas to a burner. It has been found that in. many instances children either carelessly or accidentally open a gas cook and permit. unburned or raw gas to escape from an unlighted. burner.

The escape of unburned gas from an unlighted l5 burner is extremely dangerous from the standpoint not only of asphyxiation but also from the standpoint of injury from both fire and explosion. The present invention prevents and overcomes any possibility of danger or injury occurring in the manner above described by preventing absolutely the possibility of any unburned gases escaping from any burner of the range. This safety feature is provided in the present invention by making a possible delivery of gas to any burner dependent upon the positive ignition of two pilot lights. The safety feature of the present invention is equally applicable to a gas range in which the burner valves are operated manually or are operated at a predetennined time by means of a clock or some other similar mechanical or automatic contrivance.

Having reference now to the drawings which illustrate the invention as applied to a gas range, it will be seen that A represents the cooking top portion of the range and B the oven. In accordance with common practice a plurality of burners C are positioned in the cooking top portion of the range and the oven is provided with an oven burner D having an extending lighter arm E. A constant burning pilot light F is positioned in the cooking top portion of the range centrally in respect to the several burners therein and by means of flash tubes 5 the cooking top burners are automatically ignited by this constant burning pilot light in a manner which will be hereinafter described in more detail.

The main gas manifold is indicated at G and is connected with a suitable source of gas supply (not shown) and after entering through the rear wall of the burner chamber 6 of the cooking top and extending along the side wall of the oven this manifold extends longitudinally of the burner chamber to provide a gas supply means for the several cooking top burners. The cooking top supplies gas to the mixing bell ll of the oven burner.

Positioned in the main gas manifold at a point in front of any connection between the manifold 1 and any of the burners there is what I have termed a safety valve K. The particular function and operation of this valve will be hereinafterdescribed, it being sumcient at this time to state that this valve is operated by a thermo member which has a portion extending into the heat zone of! what I have termed a safety pilot light L.

Gas is constantly supplied to the constant burning pilot light F through a conduit l2 which has connection as at l3 with the main gas manifold at a point in front of the safety valve K. The amount of fuel delivered to the safety pilot light is under the control of an adjusting valve l4 positioned in this gas line.

The gas or fuel is supplied to the pilot L through a pipe line l5 one end It of which has connection with the safety valve K and the other end I! of which (see Figure 2 of the drawings) is connected to the pilot light L. Intermediate the length of this pipe line there is positioneda thermostatically controlled valve H the operation of which is under the control of the constantly bumlng pilot light F in a manner which will be hereinafter more specifically described. An adjusting valve 3 is positioned in the fuel line l5 to the pilot light L for controlling the amount of fuel delivered to this pilot light.

Referring now in detail to the constant burning pilot light F and the valve H which is thermostatically operated by this pilot light, it will be seen by reference particularly to Figures 4 and 5 of the drawings that the pilot light itself is of more or less conventional construction in that there is a main cup l3 surrounding the main jet 20 of the pilot and that this is secured in place by a suitable nut 2|. A second and smaller cup 22 surrounds the outlet end 23 of the pilot light jet and the flame which burns at this point is for the most part fully within this cup. The cup is secured in place by a nut 24. A bi-metallic thermo member or element M has one end secured to the cup 22 as at 25 and is provided with a vertically extending portion 26 which is within the heat zone of the flame which burns at the pilot. This thermo member is of a more or less U-shape and has a downwardly extending end 21 which is adapted to operate the valve H.

The valve H comprises a body 28 which is provided with an extending portion 23 towhich is attached the inlet side of the gas line I 5 and at the oppositely extending portion 30 to which is connected the outlet side of the gas line l5. Centrally arranged within the body is a chamber 3i from which extends the channel 32 connecting the chamber with the inlet side of the gas line and the channel 33 which connects the chamber with the outlet side of the gas line. A hollow plunger 34 is reciprocable within the extending portion 35 of the valve body'and carries a coil spring 36. This plunger has a closed inner end 31 while its opposite end is open and through this open end the spring 36 extends for engagement with the under side 'of the cap nut 38 which is threadedly mounted as at 33 upon the valve body extension 35. By means of this nut the tension of the spring 36 is adjustable.

The plunger 34 serves as a valve in that it is reciprocable over the inner end of the channelway 33 for the purpose of closing this channelway against the passage of gas. The spring 33 tends to normally hold the plunger inwardly and in a position to close the passageway.

This valve fitting or body 28 is provided with an arm or bracket 40 which is riveted or otherwise suitably secured as at 4| to the large cup I! surrounding the constant burning pilot F. A valve rod 42 is reciprocable through or within this arm or bracket and has an enlarged outer end or head 43 properly positioned to be engaged by the extending end 31 of the thermo element M. The inner end 44 of the'valve rod terminates within the central chamber 3| of the valve H.

From the description thus far given it will be seen that when the constant burning pilot light is ignited the heat from the pilot light will act upon the thermo member which will in turn act upon the valve rod 42 to push the valve rod in and move the plunger valve 34 against its spring 26 to open the passageway 33 and permit the passage of gas through the valve H and to the pilot light L.

The safety valve K is illustrated in detail in Figure 3 of the drawings while its position in relation to the pilot light L is clearly shown in Figure 2 of the drawings.

Referring first to Figure 2 of the drawings it will be seen that the pilot light L is positioned within an indenture 45 provided in the wall 45 of the oven B. This indenture is in the form of a plate 4! inset in the oven wall and secured' therein by suitable bolts and nuts 43 or the like. This plate is provided with an opening 49 immediately opposite the upper end of the pilot L and in horizontal alignment with the flame 50 thereof. The lighter arm E of the oven burner extends towards and terminates just short of the opening 49 of the plate with the result that the oven burner will be ignited by this pilot when gas is supplied to the oven burner.

Both automatic and manual means are illustrated for igniting the pilot L. In Figure 1 of the drawings a flash tube P is shown as extending from the constant burning pilot light F to a point adjacent the pilot light L for igniting this pilot light automatically from the constant burning pilot light. In Figure 2 of the drawings an optional manual means is illustrated for igniting the pilot light L. In this figure of the drawings it will be seen that a conduit 5| is positioned in the oven wall and has its lower end 52 in communication with the aperture 45 within which the pilot L is located while its upper open end 53 extends outwardly through the oven wall at a point just above the surrounding frame 54 of the cooking top portion of the range. When gas is being supplied to the pilot L it will be obvious that the pilot can be ignited by applying a match to the upper open end 53 of the conduit 5|.

Describing the safety pilot valve K in detail and having reference particularly to Figure 3 of the drawings, it will be seen that this valve comprises a fitting which in part is a pipe section 55 that constitutes a continuating or a part of the main gas manifold conduit G. Intermediate the length of the conduit pipe section 55 of the valve there is positioneda valve seat 56 and a valve 51 of the poppet type which cooperates with the seat and carried an elongated stem ll which extends outwardly beyond the valve fitting and has an outer threaded end 59. The fitting immediately'above the valve seat is provided with a removable plug or nut 5.0 which is threadedly mounted in the fitting as indicated at 6|. fuel passageway 52, one end of which is in communication with the interior of the pipe section portion 55 at a point in front of the valve 51 while to its outer threaded end 63 is attached the end l6 of the fuel conduit l5 leading to the pilot light L. A coil spring 5 is positioned between the upper face of the poppet valve 51 and the under side of the cap nut 60. This spring normally tends to hold the valve in closed position upon its seat and the tension of the spring is of course adjustable by manipulation of the cap nut or plug 60.

The fuel passageway 52 which penetrates the adjustable cap nut or plug 6|! has a portion 91 extending into the safety valve housing and is in direct alignment with a cylindrical stud 98 formed on the upper face of the valve 51. This stud is of a diameter slightly larger than the diameter of the fuel passageway 52 and its upper face or end is conical as indicated at 99. The conical end of this stud is intended to act in a throttling valve manner in combination with the lower open end 91 of the fuel passageway 62 in a manner which will be hereinafter described more specifically when a description of the operation of the present invention is given.

This valve stud also serves as a positioning and retaining means for the lower end of the coil spring 64 the upper end of which encircles the extending fuel passageway portion 91, all of which clearly appears in Figure 3 of the drawings.

At its under side, the valve fitting is provided with a lug-like extension 65 having a reduced threaded portion 66 carrying a nut 51 which clamps the end 68 of the thermo element N against the lug portion of the fitting.

This bi-metallic thermo element N is of an approximate U-shape although the free end of the element is bent up slightly and forked as indicated at 69 in Figures 2 and 3 of the drawings. The threaded end 59 of the valve stem 58 extends through the forked end 59 of the thermo element and a nut 10 is adjustable on the threaded portion of the valve stem and is adapted to engage or be engaged by the free end of the thermo element. I

This thermo element is of a size or length whereby its main curved portion 1| extends into the aperture 45 at a point above the pilot L with the consequent result that when this pilot is ignited the thermo element is subjected to the heat generated by the flame at the pilot light and will operate to lift the valve 51 from its seat against tension of the coil spring 64. and permit the passage of gas through the main gas manifold G.

Having described the construction of the several parts making up the present invention, a short description will be now given of the operation of the invention. It will be assumed that the main gas manifold is connected to a suitable gas supply with the result that gas is'being conveyed by the pipe line I2 to the constant buming pilot F. Gas will of course be passing from the safety valve fitting K outwardly through the passageway 62 of the cap nut 60 and into the gas line l5 which leads to the pilot light L. With This plug or cap nut is provided with a the constant burning pilot light F burning the heat from this light has acted upon the thermo element M to open the valve H and permit the passage of gas to the pilot light L where it will be automatically ignited by the constant burning pilot F through the flash tube P or will be lighted by the application of a match to the upper end 53 of the pipe 5| in the event the.automatic lighting means for this pilot is not employed.

Thepilot L will heat the thermo element N and cause the opening of the safety valve 51 thus permitting the passage of gas into the main portion of the manifold G where this manifold has connection with the cooking top burners and with the oven burner.

With both the constant pilot F burning and the supplemental pilot light L burning any burner of the range will be automatically ignited in the event the valve controlling the flow of gas to any particular burner is opened. Thus, if the valve of one of the cooking top burners is open gas will immediately flow to said burner and will enter one of the flash tubes 5 leading to the constant burning pilot F and by reason of a flash backthrough said tube the particular cooking opening 49. The fiame will of course travel along the lighter arm E and ignite the gas issuing from the main oven burner orifices 11.

From the foregoing it will be understood that any or all burners can be instantly automatically ignited when both the constant burning pilot light F and the supplemental pilot light L are ignited thus providing an automatic lighter for both the cooking top and oven burners of the range.

It is desirable to provide means to prevent overheating and damage to the thermo element N. This is accomplished by the throttling action heretofore mentioned. As the thermo element N becomes heated from the pilot light L and opens the valve 51 the stud portion 98 of the valve moves towards the lower end 91 of the fuel conduit 52 which has connection with the gas delivery pipe to the pilot L. The hotter the thermo element becomes the nearer will be the approach of the stud 98 to the extending end 91 of the fuel conduit 52. Thus there will be throttling valve action on the gas delivery to the pilot L. The gas supply to the pilot light will never be completely shut off by this stud 98 for the reason that the thermo element N is highly sensitive to the heat of the pilot light and if the gas flame is reduced too much" by reason of the throttling action the thermo element will cool sufficiently to permit the spring 64 to move the valve 51 downwardly thus permitting an increased delivery of fuel to this pilot light. In actual practice I have found that the gas supply to the pilot light has never been completely shut off by the throttling action, but for the purposes of safety a channelway could be cut in the side of the stud to assure a passage of gas to the fuel conduit 62 even though the stud might be forced tightly against the lower end 91 of the conduit.

It will be further understood from the foregoing description that the invention in addition to providing an automatic lighter arrangement for all of the burners of a gas range provides a safety device to prevent the possibility of the escape of unburned'or raw gas from an unlighted burner. This safety feature resides in the provision of a single safety valve which is under the control of two pilot lights. If the supplemental pilot lightLis not burning the safety valve is closed and no gas can pass to any of the range burners. Furthermore, if the constantly burning pilot light is not ignited no gas can flow to the supplemental pilot light because with the constantly burning pilot light extinguished, the valve H is closed against the passage of any gas to the supplemental pilot light L. As a consequence, to obtain a flow of gas at any of the burners, other than the pilot light burners, both of the pilot lights must be ignited. It will be equally clear that with both of the pilot lights ignited it will be perfectly safe to permit the delivery of gas to any of the main burners because the constant burning pilot light will then be ever ready to automatically ignite any cooking top burner while the supplemental pilot light L stands ready to ignite the oven burner.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In combination with a stove, a plurality of cooking top burners, an oven burner, a fuel supply pipe leading to all of said burners, ignition means including a pilot burner positioned to ignite fuel flowing from any one of the cooking top burners, means including a pilot positioned to ignite fuel flowing from the oven burner, a fuel supply means leading to each of said pilots, thermostatic valve means in said fuel supply pipe positioned to be responsive to the heat of one of said pilots,

said valve means controlling the flow'of fuel to said cooking top. and oven burners and being operable to permit fuel flow as long as said one pilot is burning and to close offsaid fuel flow upon failure of said one pilot, thermostatic valve means in the fuel supply means of said one pilot responsive to the heat of the other of said pilots and operable to permit fuel flow to said one pilot only when said other pilot is burning whereby the fuel supply to said cooking top and oven burners will be cut off upon the extinguishment of either of said pilots.

2. The combination with a plurality of gas burners a gas supply conduit therefor and a shutoff valve in said conduit, of a gas lighter comprising a, plurality of lighter devices relatively positioned in igniting relationship to different burners, each device being provided with a pilot jet, means responsive to the presence or absence of flame in a certain one of said jets operative to automatically actuate said shut-oil valve when said jet is extinguished, and means responsive to the presence or absence of flame in any other of said jets to control the fuel supply to said flrst mentioned jet.

3. In combination with a stove, a plurality of cooking top burners, an oven burner, a fuel supply pipe leading to all of said burners, ignition means including a constant burning pilot light positioned to ignite fuel flowing from any one of the cooking top burners, means including a pilot light positioned to ignite fuel flowing from the oven burner, a fuel supply means leading to each of said pilots, thermostatic valve means in the main fuel supply pipe positioned to be responsive to the heat of theoven pilot light,'said valve means controlling the flow of fuel to said cooking top and oven burners and being operable to permit fuel flow as long as said oven pilot,light is burning and to close ofl said fuel flow upon failure of said pilot light, thermostatic valvemeans in the fuel supply means of said oven pilot light responsive to the heat of the constant burning pilot light and operable to permit fuel flow to said oven pilot light only when said constant burning pilot light is ignited, whereby the fuel supply to said cooking top and oven burners will be cut off upon the extinguishment of either of said pilots.

4. A construction such as defined in claim 3, wherein means is provided for automatically igniting the oven burner pilot light from the constant burning pilot light.

5. In combination with a stove, a plurality of cooking top burners, an oven burner, a fuel supply pipe leading to all ofsaid burners, a pilot burner provided with flash tubes extending towards said cooking top burners whereby said pilot burner serves as an ignition means for said cooking top burners, a pilot burner positioned to ignite fuel flowing from said oven burner, a flash tube extending from said cooking top burner pilot light to said oven pilot light whereby said last named pilot light is ignited by the first named pilot light, a fuel supply means leading to each of said pilots, thermostatic valve' means in said fuel supply pipe positioned to be responsive to the heat of one of said pilots, said valve means controlling the flow of fuel to said cooking top and oven burners and being operable to permit fuel flow as long as said one pilot is burning and to close off said fuel flow upon failure of said one pilot, thermostatic valve means in the fuel supply means of said one pilot responsive to the heat of the other of said pilots and operable to permit fuel flow to said one pilot only when said other pilot is burning whereby the fuel supply to said cooking top and oven burners will be cut off upon the extinguishment of either of said pilots.

6. In combination with a stove, a plurality of cooking top burners, an oven burner, a fuel supply pipe leading to all of said burners, ignition means including a pilot burner positioned to ignite fuel flowing from any one of the cooking top burners, a pilot positioned to ignite fuel flowing from the oven burner, a fuel supply means leading to each of said pilots, thermostatic valve means in said fuel supply pipe positioned to be responsive to the heat of one of said pilots, said valve means controlling the flow of fuel to said cooking top and oven burners and being operable to permit fuel flow as long as said one pilot is burning and to close off said fuel flow upon failure of said one pilot, and said valve means also acting to throttle the amount of fuel delivered to the oven burner pilot light as said valve means is opened to permit fuel flow to the cooking top and oven burners, thermostatic valve means in the fuel supply means of said one pilot responsive to the heat of the other of said pilots and operable to permit fuel flow to said one pilot only when said other pilot is burning whereby the fuel supply to said cooking top and oven burners will be cut ofl upon the extinguishment of either of said pilots.

. 7. In a gas range, an oven and a cooking top having a burner chamber therebeneath, a chamberformed in the oven wall and having communication at one side with the cooking topbumer chamber and at its other side provided with an opening communicating with the oven, a burner the oven wall, a plurality of burners in the-cook-- ing top burner chamber, a constant burning pilot light including means adapted to ignite fuel flowing from any one of the cooking top burners, a safety pilot light positioned in the oven wall chamber and adjacent the opening therein which communicates with the oven, means whereby said constant pilot light serves to ignite gas flowing from said safety pilot light, a main gas supply pipe for the cooking top and oven burners, a thermo operated valve in said pipe, a thermo element connected to said valve and extending into the wall chamber and into the heat zone of the burner jet of the safety pilot light, a fuel line for the safety pilot light provided with a thermo operated valve positioned adjacent the constant pilot light, and a thermo element positioned in the heat zone of the constant pilot light for actuating said last named valve, the parts operating as and for the purpose described.

8. In a gas range, an oven and a cooking top having a burner chamber therebeneath, a chamber formed in the oven wall and having communication at one side with the cooking top burner chamber and at its other side provided with an opening communicating with the oven, an outlet flue in said oven wall having one end communicating with said oven wall chamber and its opposite end with the atmosphere external of the oven, a burner in the oven and having a burner portion positioned adjacent the communicating opening in the oven wall, a plurality of burners in the cooking top burner chamber, a constant burning pilot light approximately centrally positioned in respect to said cooking top burners, flash tubes extending from said constant burning pilot light to points adjacent said cooking top burners whereby said constant pilot light serves as an ignition means for any or all of said cooking top burners, a safety pilot light positioned in the oven wall chamber and adjacent the opening therein which communicates with the oven, a flash tube extending between said safety pilot light and said constant pilot light whereby the constant pilot light serves as an ignition means for the safety pilot light, a main gas supply pipe for the cooking top and oven burners, a thermo operated valve in said pipe, a thermo element connected to said valve and extending into the wall chamber and into the heat zone of the burner jet of the safety pilot light, a fuel line for the safety pilot light provided with a thermo operated valve positioned adjacent the constant pilot light, and a thermo element positioned in the heat zone of the constant pilot light for actuating said last named valve, the parts operating as and for the purpose described.

9. In a gas range, an oven and a cooking top having a burner chamber therebeneath, a chamber formed in the oven wall and having communication at one side with the cooking top burner chamber and at its other side provided with an opening communicating with the oven, a burner in the oven and having a burner portion positioned adjacent the communicating opening in the oven wall, a plurality of. burners in the cooking top burner chamber, a constant burning pilot light approximately centrally positioned in respect to said cooking top burners, flash tubes extending from said constant burning pilot light to points adjacent said cooking top burners whereby said constant pilot light serves as an ignition means for any or all of said cooking top burners, a safety pilot light positioned in the oven wall chamber and adjacent the opening therein which communicates with the oven, a flash tube extending between said safety pilot light and said constant pilot light whereby the constant pilot light serves as an ignition means for the safety pilot light, a main gas supply pipe for the cooking top and oven burners, a thermo operated valve in said pipe, a thermo element connected to said valve and extending into the wall chamber and into the heat zone of the burner jet of the safety pilot light, a fuel line for the safety pilot light provided with a thermo operated valve positioned adjacent the constant pilot light, and a thermo element positioned in the heat zone of the constant pilot light for actuating said last named valve, the parts operating as and for the purpose described.

10. In a gas range, a cooking top and burners therefor, an oven having a burner therein, a common gas supply line for the cooking top and oven burners, a thermostatically operated valve in said gas supply line controlling the delivery of the gas to all of. said burners, a pilot light for the oven burner and for operating said thermostatic valve, a gas line to said pilot light, a second and constant burning pilot light, means whereby said constant burning pilot light will ignite the cooking top burners and the first named oven pilot light, a thermostatically operated valve in the gas line to the oven pilot light and controlling the delivery of gas to said pilot light, said valve operable by the heat from the constant burning cooking top pilot light, said first named thermostatically operated valve in the common gas supply line controlling the passage of fuel to the cooking top and oven burners and having a portion which upon opening movement of the valve acts as a throttling means against the admission of fuel to the gas line serving the oven burner pilot light, the parts operating whereby gas can be delivered to the cooking top and oven burners from the common gas supply line only when both pilot lights are ignited and gas can be delivered to the oven pilot light only when the cooking top burner pilot light is ignited.

11. In a gas range, an oven and a cooking top portion adjacent thereto and having a burner chamber therebeneath, an opening forming communication between the oven and the cooking top burner chamber, an oven burner having a burner portion positioned adjacent the communicating opening between the oven and the cooking top burner chamber, a plurality of burners in the cooking top burner chamber arranged in separated relationship, a constant burning pilot in said burner chamber, means to ignite said cooking top burners from said constant pilot light, a safety pilot light located in said cooking top burner chamber adjacent the communicating opening between said chamber and said oven and serving to ignite through said opening the oven burner, a main gas supply pipe for supplying fuel to all of the cooking top burners and the oven burner, a thermo operated valve in said pipe line, a thermo element positioned in the heat zone of said safety pilot light for operating said valve, a fuel pipe line to said safety pilot light and having a thermo operated valve therein, a thermo element positioned in the heat zone of said constant burning pilot light and adapted 

